6.
Muscles - structure

All of our muscles are made
up of microscopic
fibres, which when bundled
together are called motor
units.

These motor units (when
called upon by a nerve
impulse create movement.

The number of motor units
used depends on the
strength of the impulse and
the effort (force) required

8.
Key Concepts Review

The muscular system acts on the bones to allow us to
move, breath, eat and more.

There are at least 700 muscles in the human body which
perform a wide variety of voluntary and involuntary
functions

The muscles are made up of bundles of muscle fibres, which
the body uses to different degrees based on the demands of
a task.